Agri Spray Drones released a battery maintenance video on July 22 that every spray drone operator should watch before their next job. In it, Ken from the agricultural drone dealer holds up a battery whose female terminal fused itself onto a drone’s male connector. He pulls as hard as he can. The two never come apart.

The failure chain is simple. A dirty or worn terminal starts to arc. Arcing builds heat and deposits carbon. Enough heat welds metal to metal. A connection that arcs or welds in the air brings the aircraft down with a full chemical payload on board.

We’ve covered battery care at DroneXL before, most recently in 5 Drone Battery Safety Tips You Need To Know In The Winter, but that advice aimed at consumer pilots winterizing a camera drone. Spray drone batteries live a rougher life: dust, chemical residue, heavy current draw, and field swaps several times an hour.

Terminal Damage Spreads From Battery to Charger to Drone

A worn female terminal on a spray drone battery grinds down the male leads on every charger and drone it touches, which means one neglected battery can quietly damage the contact points across an entire operation before the operator notices anything is wrong.

The video walks through three examples. The first is obvious damage: a male terminal lead, built from two pieces of pressed metal, visibly separating. Replace it. The second looks fine at a glance but shows discoloration at the contact points. For that one, Ken demonstrates a fingernail test: press a fingernail against each pin and pull it flush along the lead, feeling for high and low spots. If every lead sits at the same height, the terminal is good. If a lead sits proud or shy, replace it.

The third example is the one that matters most: the female terminal on the battery itself. Because that terminal mates with both the charger and the drone, its wear transfers to everything it touches. Find damage there, and the video’s advice is blunt: inspect every charger and every drone that battery has ever been plugged into.

Clean First, Then Inspect for Bubbling, Pitting and Discoloration

Agri Spray Drones recommends spraying electrical contact cleaner directly into the female terminal, agitating the pins with a soft wire brush or firm nylon brush, and repeating until the liquid runs out clear, because grime hides exactly the damage an inspection is supposed to catch.

In the video, the first spray of WD-40 electrical contact cleaner flushes black gunk out of a terminal that looked serviceable from the outside. After brushing and a second flush, a microfiber cloth cleans up the seal and surface debris. In the field, a shot of compressed air dries the terminal for immediate use. At the shop, five to ten minutes of air drying does the job.

Then comes the inspection. Flip the battery terminal-side up and rotate it left and right so light catches every contact pin on both sides. Bubbled metal means arcing. So do black spots, which are carbon buildup and material transferred from the mating terminal. Pitting and discoloration on the leads mean the same. Surface grime that wipes away is fine and the terminal stays in service. Damage in the lead itself means replacing the terminal, positive and negative both.

Daily Inspections Cost Minutes, Crashed Drones Cost Seasons

The recommended cadence is a full clean and inspection at the start or end of every operating day, plus a quicker visual check between jobs, so a custom applicator flying three fields in one day would look at those terminals three separate times.

The trap is that a battery with damaged terminals will keep flying. Nothing stops you from installing it, and the drone will take off. The video’s warning is that arcing accelerates once it starts, and the fused-terminal battery shown on camera is where that road ends. Agri Spray Drones, which partnered with EAVision in early 2025 to bring machines like the EAVision J150 to American farms, sells the batteries this advice protects. The physics apply to every brand.

DroneXL’s Take

I’ve been writing battery care advice for consumer pilots every winter since 2023, and the discipline is always the same: the battery is a wear item, so treat it like one. Spray drone operators have even less room for slack. A 70-liter class machine hauling crop protection product is not a camera drone landing in a snowbank. When it comes down, it comes down heavy, and it comes down over someone’s field.

Here’s what makes this more than a maintenance tip. Agricultural aviation is the strongest argument the drone industry has right now. When the Texas Farm Bureau warned that the FCC drone ban threatens agricultural operations, it was farmers making the case for drones, not drone companies making the case for themselves. Every preventable spray drone crash chips away at that argument and hands ammunition to people who want these machines grounded. The fix shown in this video is a can of contact cleaner, a brush, and five minutes a day. That is the cheapest insurance in agriculture. Don’t be the operator who skipped it.

Source: Agri Spray Drones

DroneXL uses automated tools to support research and source retrieval. All reporting and editorial perspectives are by Haye Kesteloo.